1.Applications of the valsalva maneuver in assessing the autonomic nervous system
Annals of Clinical Neurophysiology 2026;28(1):15-21
The valsalva maneuver is a gold standard test for evaluating cardiovascular autonomic function. By inducing characteristic heart rate and blood pressure changes across four phases, it allows simultaneous assessment of sympathetic and parasympathetic responses. Quantitative indices such as the valsalva ratio, pressure recovery time, and baroreflex sensitivities provide precise evaluation of autonomic reflex pathways. Specific patterns like the square-wave phenomenon offer diagnostic clues to differentiate peripheral from central autonomic disorders. This review summarizes the physiological mechanisms underlying the valsalva maneuver, key derived metrics, and examples of its clinical applications in diagnosing autonomic dysfunction in neurological disorders, including pure autonomic failure, Parkinson’s disease, and amyotrophic lateral sclerosis. Owing to its simplicity, noninvasiveness, and diagnostic utility, the valsalva maneuver remains a fundamental tool in clinical and research settings for autonomic assessment.
2.A Practical Immunohistochemistry-Based Model for Predicting Pathologic Complete Response in Estrogen Receptor-Strong Positive and HER2-Negative Breast Cancer
Su Min LEE ; Jeong Eon LEE ; Seok Jin NAM ; Seok Won KIM ; Jonghan YU ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Eun Yoon CHO ; Hyunwoo LEE ; Woong Ki PARK
Journal of Breast Cancer 2026;29(2):128-140
Purpose:
While the benefit of neoadjuvant chemotherapy (NAC) has been established in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancers, its effectiveness in achieving pathological complete response (pCR) and optimal patient selection in estrogen receptor (ER)-positive, HER2-negative breast cancers remain less clearly defined. This study aimed to identify immunohistochemistry (IHC)-based predictors of pCR and to develop a scoring model for ER-strong positive/HER2-negative breast cancer.
Methods:
Data from a prospective cohort were retrospectively analyzed. We included 522 patients with ER-strong positive/HER2-negative tumors who received NAC and surgery between 2008 and 2021. IHC markers including progesterone receptor (PR), Ki-67, epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6), and p53 were evaluated to identify predictors of pCR. Independent predictors of pCR from multivariate logistic regression were used to develop a weighted 4-point model. Model performance was assessed using receiver operating characteristic analysis. The prognostic impact of pCR was evaluated using KaplanMeier and Cox regression analyses.
Results:
Independent predictors of pCR included PR-negative status, positivity for basallike markers (EGFR or CK5/6), and Ki-67 ≥ 50%. The scoring model demonstrated good discrimination for pCR (area under the curve = 0.754). pCR rates increased stepwise, with scores of 4.9% (low), 10.7% (intermediate), and 36.2% (high). In the high-score group, pCR was significantly associated with improved disease-free survival (hazard ratio [HR], 0.09; p = 0.023) and distant metastasis-free survival (HR, 0.11; p = 0.035), whereas no significant survival differences according to pCR status were observed in the low and intermediate score groups.
Conclusion
This IHC-based model predicts pCR and helps identify subgroups in which pCR is associated with meaningful survival benefit following NAC in ER-positive/HER2-negative breast cancers. High-scoring patients may benefit from NAC, while patients with low- or intermediatescores may be better managed with surgery and endocrine therapy. This model may support personalized treatment decisions regarding NAC.
3.Clinical Outcomes of Lobular Carcinoma In Situ: Risk of Invasive Cancer Development
Doyoun WOEN ; Ki Jo KIM ; Su Min LEE ; Seungah LEE ; Kawon OH ; Cho Eun LEE ; Seok Jin NAM ; Seok Won KIM ; Jeong Eon LEE ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Woong Ki PARK ; Hyunwoo LEE ; Jonghan YU
Journal of Breast Cancer 2026;29(2):163-174
Purpose:
Lobular carcinoma In Situ (LCIS) is a noninvasive lesion associated with an increased risk of invasive cancer. Since its removal from the tumor, node, metastasis classification in the 8th edition of the American Joint Committee on Cancer (AJCC) guidelines, the clinical management of LCIS has shifted from surgery to surveillance. However, studies focusing on the risk and associated factors for invasive cancer development in pure LCIS without ductal carcinoma In Situ (DCIS) or invasive cancer remain limited.
Methods:
We retrospectively analyzed 106 patients diagnosed with pure LCIS between 2008 and 2018. This study evaluated the effect of tamoxifen use and histologic type on the development of invasive cancer.
Results:
All 106 patients underwent surgery, and nine (8.5%) developed invasive cancer over a median follow-up of 67.5 months. The incidence of invasive cancer was lower in the tamoxifen group (6.3%, n = 4) than in the non-tamoxifen group (11.9%, n = 5), although this difference was not statistically significant (p = 0.266). Pleomorphic LCIS had a significantly higher incidence of invasive cancer (30.0%, n = 3) than classic LCIS (6.3%, n = 6) (p = 0.045).Multivariable Cox regression analysis showed no significant difference in the risk of invasive cancer according to tamoxifen use (hazard ratio [HR], 2.031; 95% confidence interval [CI], 0.544–7.579; p = 0.292). However, pleomorphic LCIS showed a trend toward an increased risk of invasive cancer compared to classic LCIS (HR, 3.856; 95% CI, 0.922–16.126; p = 0.064).
Conclusion
Postoperative tamoxifen did not significantly lower invasive cancer development in patients with pure LCIS. Pleomorphic LCIS may carry a higher risk than classic LCIS. These findings require tailored follow-up and treatment strategies based on the histologic subtype of LCIS.
4.Effects of rapid antigen testing for pre-admission COVID-19 screening: a before and after study in the emergency department
Hyunwoo LEE ; Moon Hwan KWAK ; Hyun Kyung PARK ; Chang Hae PYO ; Keun Hong PARK ; Hahn Bom KIM ; Eun Mi HAM ; Jin Hyung PARK ; Dong Sun CHOI ; Jee Hyeon KIM ; Soo Bok CHOI
Journal of the Korean Society of Emergency Medicine 2025;36(6):221-231
Objective:
As the coronavirus disease 2019 (COVID-19) pandemic has been prolonged, the pre-hospital screening test performed in hospitals has changed from polymerase chain reaction (PCR) to rapid antigen test (RAT). RAT has lower sensitivity than PCR, but a lower cost and shorter test time. In the hospital where this study was conducted, the preadmission COVID-19 test was changed from PCR to RAT on February 24, 2023. This study compared the efficacy of PCR and RAT as the pre-admission COVID-19 test.
Methods:
This was a retrospective observational study comparing two periods, 90 days from November 25, 2022 to February 23, 2023, and 90 days from February 28, 2023 to May 29, 2023. Patients hospitalized from the emergency medical center during these two periods were included. Binomial logistic regression was used to compare the emergency department length of stay (ED LOS) between the two groups (PCR vs. RAT). Logistic regression was used to compare the mortality.
Results:
Four thousand seven hundred and thirty-eight patients were admitted through the emergency room: 2,202 patients in the PCR group and 2,443 patients in the RAT group. No statistically significant differences in the characteristics and severity were observed between the two groups. The mean ED LOS of PCR 5.07 hours (interquartile range, 3.80-6.75) was longer than RAT 3.65 hours (interquartile range, 2.83-4.68) (P<0.001). Mortality was higher in PCR 8.9% than RAT 6.6% (P=0.005).
Conclusion
The study showed that ED LOS and mortality were reduced when using RAT rather than PCR as a preadmission COVID-19 test.
5.Worsening of health disparities across COVID-19 pandemic stages in Korea
Hyejin LEE ; Hyunwoo NAM ; Jae-ryun LEE ; Hyemin JUNG ; Jin Yong LEE
Epidemiology and Health 2024;46(1):e2024038-
OBJECTIVES:
With the end of the coronavirus disease 2019 (COVID-19) pandemic, the health outcomes of this disease in Korea must be examined. We aimed to investigate health outcomes and disparities linked to socioeconomic status during the COVID-19 pandemic in Korea and to identify risk factors for hospitalization and mortality.
METHODS:
This nationwide retrospective study incorporated an analysis of individuals with and without COVID-19 in Korea between January 1, 2020 and December 31, 2022. The study period was divided into 4 stages. Prevalence, hospitalization, mortality, and case-fatality rates were calculated per 100,000 population. Multivariate logistic regression was performed to identify risk factors for COVID-19 hospitalization and mortality.
RESULTS:
Overall, the incidence rate was 40,601 per 100,000 population, the mortality rate was 105 per 100,000 population, and the case-fatality rate was 259 per 100,000 cases. A total of 12,577,367 new cases (24.5%) were recorded in stage 3 and 8,979,635 cases (17.5%) in stage 4. Medical Aid recipients displayed the lowest 3-year cumulative incidence rate (32,737 per 100,000) but the highest hospitalization (5,663 cases per 100,000), mortality (498 per 100,000), and case-fatality (1,521 per 100,000) rates. Male sex, older age, lower economic status, non-metropolitan area of residence, high Charlson comorbidity index, and disability were associated with higher risk of hospitalization and death. Vaccination was found to reduce mortality risk.
CONCLUSIONS
As the pandemic progressed, surges were observed in incidence, hospitalization, and mortality, exacerbating disparities associated with economic status and disability. Nevertheless, Korea has maintained a low case-fatality rate across all economic groups.
6.Cost-Effectiveness of Age-Expanding Strategy of Latent Tuberculosis Infection Treatment in Household Contacts in South Korea
Hyunwoo CHO ; Jeongjoo SEOK ; Youngmok PARK ; Hee Jin KIM ; Eun Hye LEE ; Jungeun PARK ; Dong Ah PARK ; Young Ae KANG ; Jeehyun LEE
Yonsei Medical Journal 2023;64(6):366-374
Purpose:
The strategy of latent tuberculosis infection (LTBI) treatment in household tuberculosis (TB) contacts has been expanding in South Korea. However, there is little evidence of the cost-effectiveness of LTBI treatment in patients over 35 years of age. This study aimed to evaluate the cost-effectiveness of LTBI treatment among household TB contacts in different age groups in South Korea.
Materials and Methods:
An age-structured model of TB was developed based on the reports from the Korea Disease Control and Prevention Agency and the National Health Insurance Service. Quality-adjusted life-years (QALY) and the averted number of TBrelated deaths were estimated along with discounted costs for a measure of incremental cost-effectiveness ratios.
Results:
The number of cumulative active TB cases would decrease by 1564 and 7450 under the scenario of LTBI treatment for those aged <35 years and <70 years, respectively, relative to the no-treatment scenario. The treatment strategies for patients aged 0 to <35 years, <55 years, <65 years, and <70 years would add 397, 1482, 3782, and 8491 QALYs at a cost of $660, $5930, $4560, and $2530, respectively, per QALY. For the averted TB-related deaths, LTBI treatment targeting those aged 0 to <35 years, <55 years, <65 years, and <70 years would avert 7, 89, 155, and 186 deaths at a cost of $35900, $99200, $111100, and $115700 per deaths, respectively, in 20 years.
Conclusion
The age-specific expansion policy of LTBI treatment not only for those under 35 years of age but also for those under 65 years of age among household contacts was cost-effective in terms of QALYs and averted TB deaths.
7.Risk Stratification of Childhood Medulloblastoma Using Integrated Diagnosis: Discrepancies With Clinical Risk Stratification
Hee Won CHO ; Hyunwoo LEE ; Hee Young JU ; Keon Hee YOO ; Hong Hoe KOO ; Do Hoon LIM ; Ki Woong SUNG ; Hyung Jin SHIN ; Yeon-Lim SUH ; Ji Won LEE
Journal of Korean Medical Science 2022;37(7):e59-
Background:
Recent genomic studies identified four discrete molecular subgroups of medulloblastoma (MB), and the risk stratification of childhood MB in the context of subgroups was refined in 2015. In this study, we investigated the effect of molecular subgroups on the risk stratification of childhood MB.
Methods:
The nCounter® system and a customized cancer panel were used for molecular subgrouping and risk stratification in archived tissues.
Results:
A total of 44 patients were included in this study. In clinical risk stratification, based on the presence of residual tumor/metastasis and histological findings, 24 and 20 patients were classified into the average-risk and high-risk groups, respectively. Molecular subgroups were successfully defined in 37 patients using limited gene expression analysis, and DNA panel sequencing additionally classified the molecular subgroups in three patients. Collectively, 40 patients were classified into molecular subgroups as follows: WNT (n = 7), SHH (n = 4), Group 3 (n = 8), and Group 4 (n = 21). Excluding the four patients whose molecular subgroups could not be determined, among the 17 average-risk group patients in clinical risk stratification, one patient in the SHH group with the TP53 variant was reclassified as very-high-risk using the new risk classification system. In addition, 5 of 23 patients who were initially classified as high-risk group in clinical risk stratification were reclassified into the low- or standard-risk groups in the new risk classification system.
Conclusion
The new risk stratification incorporating integrated diagnosis showed some discrepancies with clinical risk stratification. Risk stratification based on precise molecular subgrouping is needed for the tailored treatment of MB patients.
8.Ramosetron versus Palonosetron in Combination with Aprepitant and Dexamethasone for the Control of Highly-Emetogenic Chemotherapy-Induced Nausea and Vomiting
Jin Hyoung KANG ; Jung Hye KWON ; Yun-Gyoo LEE ; Keon Uk PARK ; Ho Jung AN ; Joohyuk SOHN ; Young Mi SEOL ; Hyunwoo LEE ; Hwan-Jung YUN ; Jin Seok AHN ; Ji Hyun YANG ; Hunho SONG ; Dong-Hoe KOO ; Jin Young KIM ; Gun Min KIM ; Hwa Jung KIM
Cancer Research and Treatment 2020;52(3):907-916
Purpose:
The purpose of this study was to compare ramosetron (RAM), aprepitant (APR), and dexamethasone (DEX) [RAD] with palonosetron (PAL), APR, and DEX [PAD] in controlling highly-emetogenic chemotherapy (HEC)–induced nausea and vomiting.
Materials and Methods:
Patients were randomly assigned (1:1) to receive RAD or PAD:RAM (0.3 mg intravenously) or PAL (0.25 mg intravenously) D1, combined with APR (125 mg orally, D1 and 80 mg orally, D2-3) and DEX (12 mg orally or intravenously, D1 and 8 mg orally, D2-4). Patients were stratified by gender, cisplatin-based chemotherapy, and administration schedule. The primary endpoint was overall complete response (CR), defined as no emesis and no rescue regimen during 5 days of HEC. Secondary endpoints were overall complete protection (CP; CR+nausea score < 25 mm) and total control (TC; CR+nausea score < 5 mm). Quality of life was assessed by Functional Living Index Emesis (FLIE) questionnaire on D0 and D6.
Results:
A total of 279 patients receiving RAD (n=137) or PAD (n=142) were evaluated. Overall CR rates in RAD and PAD recipients were 81.8% and 79.6% (risk difference [RD], 2.2%; 95% confidence interval [CI], −7.1 to 11.4), respectively. Overall CP and TC rates for RAD and PAD were 56.2% and 58.5% (RD, −2.3%; 95% CI, −13.9 to 9.4) and 47.5% vs. 43.7% (RD, 3.8%; 95% CI, −7.9 to 15.5), respectively. FLIE total score ≥ 108 (no impact on daily life) was comparable between RAD and PAD (73.9% vs. 73.4%, respectively). Adverse events were similar between the two groups.
Conclusion
In all aspects of efficacy, safety and QOL, RAD is non-inferior to PAD for the control of CINV in cancer patients receiving HEC.
9.Virus-like Particle Vaccine Containing Toxoplasma gondii Rhoptry Protein 13 Induces Protection against T. gondii ME49 Infection in Mice
Hae Ji KANG ; Ki Back CHU ; Su Hwa LEE ; Min Ju KIM ; Hyunwoo PARK ; Hui JIN ; Fu Shi QUAN
The Korean Journal of Parasitology 2019;57(5):543-547
Toxoplasma gondii can infect humans worldwide, causing serious diseases in pregnant women and immunocompromised individuals. T. gondii rhoptry protein 13 (ROP13) is known as one of the key proteins involved in host cell invasion. In this study, we generated virus-like particles (VLPs) vaccine expressing T. gondii rhoptry ROP13 and investigated VLPs vaccine efficacy in mice. Mice immunized with ROP13 VLPs vaccine elicited significantly higher levels of T. gondii-specific IgG, IgG1, IgG2a, and IgA antibody responses following boost immunization and challenge infection, whereas antibody inductions were insignificant upon prime immunization. Differing immunization routes resulted in differing antibody induction, as intranasal immunization (IN) induced greater antibody responses than intramuscular immunization (IM) after boost and challenge infection. IN immunization induced significantly higher levels of IgG and IgA antibody responses from feces, antibody-secreting cells (ASCs), CD4⁺ T, CD8⁺ T cells and germinal center B cell responses in the spleen compared to IM immunization. Compared to IM immunization, IN immunization resulted in significantly reduced cyst counts in the brain as well as lesser body weight loss, which contributed to better protection. All of the mice immunized through either route survived, whereas all naïve control mice perished. These results indicate that the ROP13 VLPs vaccine could be a potential vaccine candidate against T. gondii infection.
Animals
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Antibody Formation
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Antibody-Producing Cells
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Body Weight
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Brain
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Feces
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Female
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Germinal Center
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Humans
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Immunization
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Immunoglobulin A
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Immunoglobulin G
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Mice
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Pregnant Women
;
Spleen
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T-Lymphocytes
;
Toxoplasma
10.A Pilot Project of Systematic Tuberculosis Screening in the Elderly in a South Korean Province
Hyunwoo KIM ; Hee Jin KIM ; Kyung Hyun OH ; Hwan Wook OH ; Hongjo CHOI
Tuberculosis and Respiratory Diseases 2019;82(3):194-200
BACKGROUND: Tuberculosis (TB) is a major infectious disease in South Korea causing substantial disease burden, particularly in the elderly. This study aimed to identify the case detection rate of mobile TB screening for the elderly conducted in the Jeollanam-do region and to analyze risk factors of active TB. METHODS: We screened the elderly population (≥65 years old) in Jeollanam-do from August to December 2017. Chest radiography was performed for all participants. Participants with TB presumptive signs were asked to submit sputum specimen(s). Sputum smear, culture, and polymerase chain reaction analyses were performed. Cascade analysis, chi-squared tests, and Fisher exact tests were used to evaluate screening performance. RESULTS: In total, 12,402 participants were screened, and 211 (1.7%) were suspected to have active TB; 181 of the suspected patients (85.8%) underwent sputum smear test, and 16 (8.8%) patients were confirmed to have TB. The TB prevalence among the elderly was bacteriologically confirmed to be 129 per 100,000 individuals, which was similar to national TB notification data for the same age groups. The proportion of active TB cases increased with age, and differed based on sex and past TB history. However, TB-related symptoms, comorbidity status, and TB screening history within 12 months were not predictive of active TB. CONCLUSION: This study identified that the prevalence rate was similar to national TB notification data from the same age groups. Periodic, community-based, systematic TB screening among the elderly population is recommended.
Aged
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Asian Continental Ancestry Group
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Communicable Diseases
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Comorbidity
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Humans
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Jeollanam-do
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Korea
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Mass Screening
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Pilot Projects
;
Polymerase Chain Reaction
;
Prevalence
;
Radiography
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Risk Factors
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Sputum
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Thorax
;
Tuberculosis

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